/Engine/Source/Runtime/Engine/Classes/Kismet/KismetMathLibrary.h
Example: LocalToWorld = ComposeTransforms(DeltaRotation, LocalToWorld) will change rotation in local space by DeltaRotation. Example: LocalToWorld = ComposeTransforms(LocalToWorld, DeltaRotation) will change rotation in world space by DeltaRotation.
New transform: A * B
static FTransform ComposeTransforms ( const FTransform & A, const FTransform & B )